Ultra-Compact Ultra-Wideband Bandpass Filter Based on Multi Mode Resonator Concept

Document Type : Research Paper


Department of Electrical Engineering, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran.


An ultra-compact ultra-wide band (UWB) bandpass filter (BPF) with a very sharp
rejection for the high-speed wireless communication applications is proposed. The
functional basis of the proposed structure is based on the multi-mode resonator (MMR)
technique. The suggested ultra-wideband filter is realized by using two doublet parallel
coupling lines, two symmetrical open stubs and tri-section step-impedance open stubs
which are located at the center of the configuration. In order to analyze the suggested
configuration, the even-mode and odd-mode methods have been utilized because of the
proposed UWB BPF is a symmetrical structure. Five modes which are including three
even modes and two odd modes have been placed within the UWB band. By changing the
dimensions of the tri-section step-impedance open stubs and two symmetrical open stubs,
the resonant modes of the constructed MMR can be tuned. These two parts have been
mainly applied to adjust the resonant modes into desired passband. Changing the
dimensions of the two symmetrical open stubs affects both the even and odd modes. But
the tri-section step-impedance open stubs can only specially control the even-mode
resonant frequencies, whereas the odd-mode ones are fixed. Consequently, the center
frequency and the bandwidth of the proposed configuration can be simply adjusted.
Experimental verification is provided and a reasonable agreement between simulated and
measured results has been achieved. The proposed UWB BPF has a passband covers 3.55
to 10.65 GHz and the measured 3 dB fractional bandwidth (FBW) is about 100%.


1- Federal Communications Commission, Revision of part 15 of the Commission’s rules regarding ultra-wideband transmission systems, Tech. Rep., ET-Docket 98-153, FCC02-48, Apr. 2002.
2- Siang-Wen Lan, Min-Hang Weng, Cheng-Yuan Hung, and Shoou-Jinn Chang, "Design of a compact ultra-wideband bandpass filter with an extremely broad stopband region," IEEE Microwave and Wireless Components Letters, vol. 26, no. 6, pp. 392-394, May 2016.
3- Li Yang, Lei Zhu, Wai-Wa Choi, Kam-Weng Tam, Runqi Zhang, and Jianpeng Wang, "Wideband microstrip-to-microstrip vertical transition with high filtering selectivity using open-circuited slot-line SIR," IEEE Microwave Wireless Compon Lett, 27, no. 4, pp. 329-331, March 2017.
4- Kumari, M. Pal, P. Sarkar, and R. Ghatak, “UWB bandpass filter with dual‐notch bands using asymmetric tri‐section stepped impedance resonator,” Intern. Journal of RF and Microwave ComputerAided Engineering, vol. 28, no. 6, pp. e21292, Aug. 2018.
5- Minjae Jung and Byung-Wook Min, "A highly selective UWB bandpass filter using stepped impedance stubs," Journal of Microwave and Wireless Technologies, vol. 10, no. 3, pp. 301-307, April 2018.
6- Zhang, M. Tian, Z. Long, M. Qiao, Z. Fu, “High-temperature superconducting multimode ring resonator ultra-wide band bandpass filter,” IEEE Microwave and Wireless Components Letters, vol. 28, no. 8, pp. 663-5, June 2018.
7- Kazemi, S. Lotfi, H. Siahkamari, and M. Mohammadpanah, "UWB Bandpass Filter with Ultra-wide Stopband based on Ring Resonator," Frequenz, vol. 72, no. 5-6, pp. 245-252, April 2018.
8- Khalilpour, “A compact and sharp ultra-wide bandpass filter by using short-stub-loaded rectangular ring and split ring resonators,” Electromagnetics, vol. 38, no. 6, pp. 352-65, Aug. 2018.
9- Wang, L. Jing, W. Huang, and F. Tan, "Ultra-Wideband Filter with Dual Notch Bands Based on Ring Resonator," Electromagnetics, vol. 37, no. 4, pp. 212-223, May 2017.
10- Huang, Zhen Hai Shao, and Z. Chen, "Miniaturized wideband bandpass filter with enhanced selectivity and stopband suppression," Microwave and Optical Technology Letters, vol. 60, no. 3, pp. 769-772, March 2018.
11- Chun-Xia Zhou, Pei-Pei Guo, K. Zhou, and W. Wu, "Design of a compact UWB filter with high selectivity and super wide stopband," IEEE Microwave and Wireless Components Letters, vol. 27, no. 7, pp. 636-638, June 2017.
12- Shang, W. Feng, and W. Che, "Wideband reconfigurable bandpass filter using coupled lines loaded with varactor loaded stubs," Intern. Journal of RF and Microwave ComputerAided Engineering, vol. 28, no. 2, pp. e21195, Feb. 2018.
13- Zhou, H. Li, Z. Long, H. Wu, T. Zhang, and M. Qiao, "Compact high temperature superconducting multi-mode ultra-wideband filter," Microwave and Optical Technology Letters, vol. 61, no. 2, pp. 357-360, Feb. 2019.
14- Shang, B. Wei, X. Guo, B. Cao, X. Wang, L. Jiang, and X. Lu, “Superconducting wideband bandpass filter based on triple-mode resonator,” IEEE Microwave and Wireless Components Letters vol. 28, no. 7, pp. 588-90, June 2018.
15- Huang and S. Zhang, "Ultra-wideband ridged half-mode folded substrate-integrated waveguide filters," IEEE Microwave and Wireless Components Letters, vol. 28, no. 7, pp. 579-581, May 2018.
16- Ma, B. Wei, X. Lu, Z. Xu, X. Wang, S. Shang, Bo Li, X. Guo, and B. Cao, "Synthesis Design of Wideband High-Selectivity HTS Filter by Cascading Dual-Mode Resonators," IEEE Trans. Applied Superconductivity, vol 28, no. 5, pp. 1-7, March 2018.
17- Danaeian, E. Zarezadeh, M. H. Gholizadeh, A. R. Moznebi, and J. Khalilpour, "A Compact and Sharp Rejection Ultra-Wideband Bandpass Filter Based on Short and Open Stub-Loaded Multiple Mode Resonators," Journal of Electrical Engineering & Technology, vol. 15, no. 1, pp. 469-476, Jan. 2020.
18- Danaeian, A. Ganji Ashkzari, K. Afrooz, and A. Hakimi, "A Compact Wide Bandpass Filter based on Substrate Integrated Waveguide (SIW) Structure," Journal of Communication Engineering, vol. 4, no. 2, pp. 132-141, July-Dec. 2015.
19- Jamal Borhani, M. Amin Honarvar, and M. R. Namazi-Rad, "A Compact UWB Bandpass Filter with High Selectivity and Dual Notched-Band," Journal of Communication Engineering, vol. 4, no. 2, pp. 100-110, July-Dec. 2015.
20- Hajebi, E. Zarezadeh, and F. Babaeian, "A Compact Ultra-Wideband Filter Based on Left Handed Transmission Line by Using Complementary Split Ring Resonators and Series Capacitor," Journal of Communication Engineering, vol. 4, no. 2, pp. 111-121, July-Dec. 2015.